Add IPC interface for switching the audio output device for a given audio stream in the browser.

content/browser/media/media_internals.cc

Index: content/browser/media/media_internals.cc
diff --git a/content/browser/media/media_internals.cc b/content/browser/media/media_internals.cc
index c3b87ce94851c3ed495b92c0499e4e1862646d6b..d622820a3915a9e72172d0e71dac0e2d1ffa7102 100644
--- a/content/browser/media/media_internals.cc
+++ b/content/browser/media/media_internals.cc
@@ -102,6 +102,8 @@ class AudioLogImpl : public media::AudioLog {
   void OnClosed(int component_id) override;
   void OnError(int component_id) override;
   void OnSetVolume(int component_id, double volume) override;
+  void OnSwitchOutputDevice(int component_id,
+                            const std::string& device_id) override;
 
   // Called by MediaInternals to update the WebContents title for a stream.
   void SendWebContentsTitle(int component_id,
@@ -187,6 +189,16 @@ void AudioLogImpl::OnSetVolume(int component_id, double volume) {
                                        kAudioLogUpdateFunction, &dict);
 }
 
+void AudioLogImpl::OnSwitchOutputDevice(int component_id,
+                                        const std::string& device_id) {
+  base::DictionaryValue dict;
+  StoreComponentMetadata(component_id, &dict);
+  dict.SetString("device_id", device_id);
+  media_internals_->SendAudioLogUpdate(MediaInternals::UPDATE_IF_EXISTS,
+                                       FormatCacheKey(component_id),
+                                       kAudioLogUpdateFunction, &dict);
+}
+
 void AudioLogImpl::SendWebContentsTitle(int component_id,
                                         int render_process_id,
                                         int render_frame_id) {